When a 2-foot square, 1/2-inch thick glass lite dropped 29
floors from Chicagos CNA Building (see
October 1999 USGlass, page 13), building management knew they had to take
precautions to prevent such an incident from reoccurring. After several months of testing,
management decided that applying window film on the buildings interior windows was
the best solution.

According to CNA chief safety officer Bill Phillips, Specialty Protective Products of
Bloomfield, Mich., has begun installing 3Ms 6-mil window film on most of the
buildings interior windows. Phillips has set the target date for installation as
early September to late October.

The only areas where window film is not being applied is on some of the lower floors.
Here, the insulating glass units are being replaced because, according to Phillips,
these are older units where film will not work as well.

The decision to install window film was made after the architectural firm of Wiss,
Janney, Elstner Associates Inc. analyzed a number of options. From the standpoint of
preventing glass from falling, window film was the best option, said Phillips.
They [Wiss, Janney, Elstner Associates Inc.] were in strong favor of installing
window film ... We ran a series of tests and found film to be a good way to offer
increased protection.